Process for the production of vat dyestuffs



Patented Jan. 1, 1929.

UNITED STATES PATENT, OFFICE,

enons mmscmm, or rmxronr on-rnn-mum'mn nunonr mil-innit, or mam,

\ KUR, NEAR FBANKFORT -ON-THE-MAIN, GERMANY, ASSIGNOBS TO GRASSELLI DYE- STUFF CORPORATION, OF NEW Y., A CORPORATION OF DELAWARE.

rnocnss r03 ran rnonpcrron or var'nxnsrurrs.

R0 Drawing. application filed. October 1, 1925, Serial No. 59,931, and. in Germany November 12, 1924.

In Letters Patent 1,440,883'a process for the production of yellow vat dyestuifs is described, which consists in heating to elevated temperatures 2-methylanthraquinone with sulfur and such aromatic compounds which contain in their molecule the paradiamine- Now we have found that analogous dyestuffs are obtained if in this process the aromatic paradiamino compounds are replaced by a primary aromatic diamino compound containing a naphthalene nucleus of the formula:

in which the 1 and 8 positions may be con- .densed by the residue of the formula:

two hydrogen atoms belonging to difierent rings of the system being replaced by aminogroups. The process for the manufacture of the new dyestufis is carried out in'the same manner as indicated 4 in Letters Patent 1,4A0,883. The shade of the dyestuffs thus obtained varies from yellow to orange.

E wample 1. i

- with a dissolving agent for sulfur, for instance by warming it with a solution of sodium sulfide. The dyestufis'thus obtained still contains brown coloringby-products.

In'order to remove them the dye-stuif is dis-.

' solved in about 10 partsconcentrated sulfuric acid then heated for, several hours toel00- 120, preferably with the addition-of a'small quantity of an acid oxidizing agent such as .chromic-acid, nitrite of sodium etc. The solution thus obtained is thereupon precipitated with water, whereby it is obtained in a'finely divided state. This paste is then further treated at 60-100 C. with a suitable alkaline o x1d1z1ng agent, as for instance with a solut on of sodium hypochlorite until the impurities have been removed and a test dyeing yields a pure yellow shade. j

The dyestufi in a purestate represents a yellow-brown powder very sparingly soluble in organic solvents, dissolving in concentrated sulfuric-acid with an orange color and dyelng cotton from a brown red vat reddish yellow shades fast to washing, chlorine and light.

f Example 2. Whenreplacing the 16 kilos 1.5 n-aphthylenediammeused-in'Example 1 by 26 kilos diaminobenzanthrone obtainable by reducing the dinitrocompoun'd of 268 C. melting with a nitric acid of 87% strength according to Example 5 of British specification No.

12518/06 and workingin'the same manner as described in Example 1 a reddish brown powder is obtained dissolving in concentrated sulfuric acid with a yellowish red color and yielding with'alkaline hydrosulfites a brown colored vat from which vegetable fibres are dyed brownish orange shades of very good fastness.

Having now particularly described and ascertained the nature of our said invention and in what manner the same'is to be' performed, we declare, that whatweclaim is:

, point, obtainableby nitrating benzanthrone I 1. Process for producing yellow to orange vat dyestuffs, which consists in heating to temperatures above 200 C. 2-methylanthra-' quinone with sulfur and a primary aromatic diamino compound, containing a naphthalene nucleus of the formula:

8 1\ 7- 2 L T i in which the 1 and 8 positions may be con densed by theresidue of the formula two hydrogen atoms to 'diflerent I in which the 1 and maybe con;

{two hydrogen atoms belonging' to difienent' densed by the residue of tbeiormula:

rings of the'system be ng replaced by groups, substantially; as described.

3. As new products the dyemufis Obtained by heating to elevated temperatures 2-methylanthraquinonewith sulfur and a primary amino aromatic diamino gcompound' conta ning a naphthalene nucleus of the formula:-

in whichjth e 1 and 8 positions may be condensed by the residue of the formula:

trated sulfuric acid with an oran v dish color and yield with alkaline ydrosulj ace-r3011 two hydrogen atoms belonging to different replacedby amino q rings of the system bein replaced by amino groups, and purifying e products thuslohtained dizi agents 511 tially; as described, whic dyestuffs are insoluble in-water and inmost organic solvents,- soluble in conca- -to r fites brown to red.' colored vats-from which "ve blefita'es are dyed yellowish to orange shades, fast to washing, chlorine and light, substantially asdescribed.

4. Process of producin an orange vat dye by treating them with alkaline oxistufi which consists'in eating to 'tempera'- tures1above-200 G. -2-methylanthraqu1none with sulfur and di 268 melting point and puri obenzanthrp'ne obtainable'b .reducing t e dinitrocom ound of I ing the- I product thus obtained by treating it with an oxidizingagent, substantially as described. j 5. As' a new product the dyestufi ,whichmaybe obtained by heating to elevated temperatures Q-methylanthtaquinbne with'sulfurobtained by e ting it with an. oxidizing agent substantially as described, which dyetufl is insoluble in water and in most organic solvents-which dissolves in'concen trated sulfuric acid with a yellowish red color and-yields with alkaline h drosulfitesa-brown colored vat from whic fibres are dyed brownish orange sha es fast to chlorine and substantially as dmcri wit-11,8 8. whereof/we have hereunto signedour names 18th'day of Septem- 'GEORG KALIscH R; BUDOLF UL ER.

and diaminobenzanthrone obtainable by re-" e dinitrocompound of '268'C;.:melt- .mgr poin and purify ng the product thus 70 v table 

